I havent personally tried either but a friend of mine bought a tub of cellucor m5 and swears by it. I will most likely snag a scoop from him in the next couple of days and try it for myself. He says the pump he gets from it is amazing. The taste apparently isnt the greatest, but thats not why we drink em, right? I havent heard anything about pre surge unleashed...Why not go with the cellucor m5 if you have the exta cash to shell out. If you do, let me us know how it treats ya.

Cool that you pointed out the GPLC as it's awesome for pumps, one of the few products that's proven to do so and definitely enhances work effort through a reduction in lactic acid buildup, reference here, luckily enough there's a hefty dose in my Pre-MAX